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SSJAIL

So @[email protected] I know you said you may have Tony redo the guides, but I think I have a one-off (or close to) system so I have a question on how to run it with stock VC.

My low side is externalized using your parts (8an PCV delete > 8an hose w/ inline 2jz valve > can > VTT check valve > TB adapter) but my high side is a bit more complicated. Essentially it's a modified version of the VS breather setup so I can run vacuum on low side and full VTA on boost. Its running as such:
Stock flapper > 10AN line > breather can w/ filter on top ("center" of my high side setup)< 10AN line with 10AN VTT check valve stopping flapper from pulling air from anything other than breather filter < 10AN fitting on front of head. I also have your oil cap breather for more venting.

Would I just pull off the flapper and run a Y like mentioned above still? So basically flapper delete > Y with one side going to this valve, and the other running to my can? Or would I need to add a check valve on the can-side of the Y still? Only reason I'm confused is because it sounds like if I had a check valve on the can side of the Y prior to the can ( Y > vacuum valve, Y > check valve > breather can) I would no longer have a vacuum source due to the only inlet/filter being blocked by the check valve. Or am I still misunderstanding, and this valve would now be my entire source of vacuum for the system rather than the breather filter providing the inlet for vacuum? If the latter is the case, would I just move the check valve from the head port side of my dual input can to the (currently) flapper/CCV side since theres no vacuum being pulled from the can? Or would I need to add an additional check valve, thus having one on both sides of the breather can?

I know you guys like to KISS when it comes to PCV at VTT, and it sounds like for your system on a stock VC this would just plug into the outlet on your CC. But I like having all the extra venting for safe measure so I'd rather not get rid of the dual inlet breather can setup if possible, however I've always wondered if I'm pulling enough vacuum with my current setup. I dont experience any smoking or other vacuum-deficient symptoms right now so I know it's at least okay, but if I could get more ring seal etc out of my setup I'm okay with a hair more tweaking.

Were gonna keep it consistent here. With the crankcase breather in the oil cap opening, and a breather on top of your can. Literally ALL you need is the -10 an check valve so it holds vacuum in the crankcase at idle, off throttle conditions. Under boost, and crankcase pressure situation. That breather is similar in size to a -22 fitting, it can vent a TON of volume. You also have the -10 hose to the breather on the can when positive pressure is present. Y, fitting for what? You are looking for positive vacuum pulling on the crankcase at idle, and off throttle conditions, and as much venting as you need under boost, etc. That set up will provide that. Nothing else is needed. I would make a diagram but away from the computer. Just take our external pcv stock valve cover vtt on the high side guide, and add a -10 check valve on the high side, a vacuum relief.

Lieutenant

Were gonna keep it consistent here. With the crankcase breather in the oil cap opening, and a breather on top of your can. Literally ALL you need is the -10 an check valve so it holds vacuum in the crankcase at idle, off throttle conditions. Under boost, and crankcase pressure situation. That breather is similar in size to a -22 fitting, it can vent a TON of volume. You also have the -10 hose to the breather on the can when positive pressure is present. Y, fitting for what? You are looking for positive vacuum pulling on the crankcase at idle, and off throttle conditions, and as much venting as you need under boost, etc. That set up will provide that. Nothing else is needed. I would make a diagram but away from the computer. Just take our external pcv stock valve cover vtt on the high side guide, and add a -10 check valve on the high side, a vacuum relief.

Sorry, maybe I'm misunderstanding due to the phone-typing or maybe I didnt explain my setup enough but I'm still a bit confused on where the vacuum relief would go and where I'd need another check valve?

The first part of your post it sounds like you're saying my setup is good since I have the venting and a -10 C.V., which I agree with - I'm all happy with my venting. However my source of vacuum is also the breather on my catch can right now which is where I'm getting confused because my impression is the vacuum relief needs to be exposed to the atmosphere - it almost sounds like you're saying to run another -10 VTT check valve instead of the flapper and run the vacuum relief in-line but then I wouldn't have any vacuum due to the check valve blocking anything coming in from the breather can.

Even just a written response of how to pipe it would be appreciated - e.g. flapper delete > relief valve > can < 10an CV < 10an hose from head port.

Sergeant

Sorry, maybe I'm misunderstanding due to the phone-typing or maybe I didnt explain my setup enough but I'm still a bit confused on where the vacuum relief would go and where I'd need another check valve?

The first part of your post it sounds like you're saying my setup is good since I have the venting and a -10 C.V., which I agree with - I'm all happy with my venting. However my source of vacuum is also the breather on my catch can right now which is where I'm getting confused because my impression is the vacuum relief needs to be exposed to the atmosphere - it almost sounds like you're saying to run another -10 VTT check valve instead of the flapper and run the vacuum relief in-line but then I wouldn't have any vacuum due to the check valve blocking anything coming in from the breather can.

Even just a written response of how to pipe it would be appreciated - e.g. flapper delete > relief valve > can < 10an CV < 10an hose from head port.

Wait for Chris to reply but i think its out of highside the Vac Relief then checkvalve going into in on catchcan.so under idle the checkvalve will close and the Vac Relief will do its job,Then under Load the check valve will open into Catchcan doing its job.

Lieutenant

Wait for Chris to reply but i think its out of highside the Vac Relief then checkvalve going into in on catchcan.so under idle the checkvalve will close and the Vac Relief will do its job,Then under Load the check valve will open into Catchcan doing its job.

That would work for a can like the newer VS can and several others, but I have a giant push-in breather on top of mine instead of another AN fitting for an outlet - hence why I'm confused as to how I'd pipe this in to my system.

SSJAIL

I honestly cannot break down your system, but I believe I understand what you are looking for. Follow our guide for external pcv dual can vta stock valve cover. Put your -10 checkvalve in the -10 hose with the arrow pointing away from the valve cover. Drill, and tap your vc for the vacuum relief. You now have a complete sealed system, that will hold the vacuum you set at idle, etc, and vent through the breather, and can under boost conditions. That is how we are going to run all our cars not running an external vacuum pump going forward

Major

I've actually looked into the T piece idea yesterday and I personally wouldn't recommend it as the valve cover opening is the restriction, whilst the line and T piece would see the full vacuum
the actual crankcase could/would possibly not due to the valve cover restriction.

If you want proper metering of vacuum in the engine you will have to mount the relief valve on the valve cover or modify your oil cap to mount it.

I think drilling the valve cover would offer a cleaner solution which is why Chris suggested it, but I'd rather avoid doing that too and I was thinking along the same lines as you in regards to getting it to work for my current set up. If I end up going with an aluminum VC I could see running it in the VC for a clean-and-final setup though.

@martymil , you posted seconds before I did so I didnt see your post. Is the opening really that much of a restriction? I thought the flapper hole was the issue, hence why VTT recommends replacing the flapper and piping this in to one of their PCV setups on the high side. If the CCV vent hole in the VC was too small why wouldn't more people be running smaller line sizes out of it than -10, not to mention shouldn't the relief valve pull x amount of vacuum from the inside of the VC regardless of whether or not the orifice is a bit smaller? I cant imagine a slight step down where the OE flapper was meant to lock in would make that significant of a difference on the overall vacuum being pulled on the crankcase, but I could be very wrong.

10 Sec Club(N54)

This is cool , especially for higher power cars, where the factory vacume relief 'might' go out of whack? It would be good to understand and see some measurements of what actually does happen to our motors in upgrade situations. This just means higher cylinder pressures will naturally increase the sealing work of rings and introduce more blowby to deal with . The N54 has at least got a somewhat decent abillity and system from factory by the looks. Spare a thought for lots of motors that have completely crap designs.

I think its been mentioned but, just to put simply the 'right' crankcase vacume levels helps the ring seal qualities and of course deal with blowby . You get some small power gains from this type of valve regulating the optimum level( tiny ones relatively speaking) 'if' you are outside of this . Im not a believer that you are going to get oil starvation levels on the N54 , so its not motor insurance, thats a very long bow to pull .
In other drag/race high power applications going "vacume pumps" allow some further options on ring selections to minimise frictional loss and seal qualities. There you are talking 2-4% gains in power and lots less wear on the rings at full tilt, with a totally optimised system. The optimisation however involves logs from measuring the crankcase vacume during runs. Race teams chasing the last bit of power in restrictive classes of racing are usually all over it.

In summary the unit looks and functions alot like the moroso ones and its priced competitively to them and VTT have done some helpful work on reccomending some appropriate shim selection. Set and forget.
Id just be interested in the quantitative measurements on stock vacume levels to see what its mitigating.

Captain

The issue you could see running the relief valve on a tee is the flow rate of the line vs the relief valve being installed directly into the VC. The more direct the relief valve to the crankcase, the faster it can bleed of excess vacuum.

Captain

This is cool , especially for higher power cars, where the factory vacume relief 'might' go out of whack? It would be good to understand and see some measurements of what actually does happen to our motors in upgrade situations. This just means higher cylinder pressures will naturally increase the sealing work of rings and introduce more blowby to deal with . The N54 has at least got a somewhat decent abillity and system from factory by the looks. Spare a thought for lots of motors that have completely crap designs.

I think its been mentioned but, just to put simply the 'right' crankcase vacume levels helps the ring seal qualities and of course deal with blowby . You get some small power gains from this type of valve regulating the optimum level( tiny ones relatively speaking) 'if' you are outside of this . Im not a believer that you are going to get oil starvation levels on the N54 , so its not motor insurance, thats a very long bow to pull .
In other drag/race high power applications going "vacume pumps" allow some further options on ring selections to minimise frictional loss and seal qualities. There you are talking 2-4% gains in power and lots less wear on the rings at full tilt, with a totally optimised system. The optimisation however involves logs from measuring the crankcase vacume during runs. Race teams chasing the last bit of power in restrictive classes of racing are usually all over it.

In summary the unit looks and functions alot like the moroso ones and its priced competitively to them and VTT have done some helpful work on reccomending some appropriate shim selection. Set and forget.
Id just be interested in the quantitative measurements on stock vacume levels to see what its mitigating.

I was thinking 02 sensor 90 degree bung with a jam nut. Not sure how a straight out, like above, would clear, once you got the relief valve on. There are right angle bungs, but I might favor this Vibrant. Need to take a look tomorrow.

Lieutenant

The issue you could see running the relief valve on a tee is the flow rate of the line vs the relief valve being installed directly into the VC. The more direct the relief valve to the crankcase, the faster it can bleed of excess vacuum.

I have a -10AN fitting running from that magic head port for ventilation, would using something like a billet Y piece there work okay? I'm talking a fitting not necessarily hose. That would actually be even easier for me since that's the side of my ccv can that already has a check valve in place.

I have a -10AN fitting running from that magic head port for ventilation, would using something like a billet Y piece there work okay? I'm talking a fitting not necessarily hose. That would actually be even easier for me since that's the side of my ccv can that already has a check valve in place.

Even if mounted on a can it would still work. It will just work best mounted to the actual crankcase/VC. If. Your adamant about not attaching it to the VC or oil cap, the closer you get it, the better.

Lieutenant

I have the VTT oil cap breather and I like to make sure I have 0 crankcase pressure so I can't mount it there - I suppose if I eventually buy an M18 VC I could drill and tap it for this since the oil cap breather wont work with that VC, but idk if I'll even do that. I'd rather the VTT VC drop in price and save my money for that eventually, but that's neither here nor there I suppose.

I just dont feel comfortable drilling and tapping a plastic VC tbh, I know several people have done it for a variety of reasons (usually PCV or VTA reasons at that) but with how prone even the stock PCV system ports are to cracking with even a slight mishap, I'd be worried that I'd end up cracking the VC or stripping the thread if I was tired or working on the car in the winter since the top of the VC would have less room for threads/less thickness than the stock PCV port. I replaced my PCV valve, then went RB external, removed that and installed the VTT PCV port, disconnected and reconnected my -8 hose end from the VTT port several times while working on the car etc with absolutely 0 issues, and then one random winter day when swapping from a 90° to a straight AN hose fitting as the last bit for the day, of course I cracked the PCV port. I learned early on in my car modding journey not to over-torque things especially when screwing into plastic but of course I was struck with bad luck eventually. My point is I'm not sloppy or brute force-ing anything into my car, but I'd hate to go through that more than once since replacing a VC can be both time consuming and costly when you arent planning on doing it.

I guess I misunderstood you at first though - my impression was you were saying that the valve would not allow proper vacuum levels to be pulled per shim if not directly in the VC, not that it would just be a slight change in time to vacuum relief. I'd imagine with all the check valves in place (one on either side of each can) that the time to vac relief would still be pretty quick either way though.

Sergeant

@fillipo I think that might work nicely, it.looks.like you would have to "clock" it so that it faces down towrad the frame rail etc.. but with the oil cooler lines removed and a couple indexing washers, seems doable.